I've done my best to remove lost motion in the rear brake assembly, had new linings fitted, put shims on the shoes, centralised them etc. But there was a vast amount of movement of the foot pedal between the shoes being just clear of the drum and coming on properly. I suspect it was designed like this as I understand the rear brake was always the one of choice in pre-war years. And I get the feeling that rather than keeping the foot on the footrest, applying the brake was more of a whole foot on the pedal.
When I had a good look at what was going on, it was clear that there was a huge mechanical advantage between the pedal and the operating cam. So I've made a little extender out of 1/8" stainless to reduce the advantage (and hence travel) by about half.
(http://i43.photobucket.com/albums/e398/iansoady/bike/Sunbeam/rear%20brake/fe1c1a66-1b1d-4756-8894-584733bc5372_zpstgpl4d3s.jpg)
(http://i43.photobucket.com/albums/e398/iansoady/bike/Sunbeam/rear%20brake/IMG_2565_zpsk18vac8p.jpg)
It'll be a little while before I'm on the road, but if I discover it's no good then it's a very simple matter to revert to standard.
Yes,,very easy to lock my back wheel because of the mechanical ratio of the lever. No rash stabbing at the pedal in an emergency :o..John